How much is this bass worth?

I recently bought a 1978 Fender P bass for £300 complete with a Vox amp, only with the intention of selling them on for a higher price.

The bass is in fair condition with a Fender hardcase. Its a USA model 2. I took it to a local music store and it was valued at about £800. I was just asking your opinion on what you think it would be worth
thanx
matt

i am going to put a 78 p-bass on law-away. for $600. and it is a refin. with a non original pickgaurd.
it is too small. so the num nuts redrilled holes for the new screws. i think i can talk him down. to maybe $400. i hope